1. Field of the Invention
The present invention is related to a method to operate an internal combustion engine having electronic control to detect emissions, compare the emissions to stored emissions at given engine speeds and torques, and derate the engine if the actual emissions are outside the range of calculated emissions for a given engine speed or torque.
The present invention further relates to a method to operate an electronic controlled internal combustion engine to detect failures or impending failures in an emission system and derate at least one of engine speed and engine torque by an amount sufficient to reduce emissions levels to calibrated emissions levels and render an indication to an operator of the failure or impending failure. Once the engine is serviced, the sensed failure repaired, or at the next ignition cycle, whichever is first, the engine can be re-calibrated or reset to operate without derate of at least one of engine speed and engine torque.
2. Description of the Related Art
Tani et al., U.S. Pat. No. 7,168,240 discloses a control apparatus for an internal combustion engine that can detect degradation of a three-way catalyst with high accuracy and without causing deterioration in an exhaust. A pair of first and second air fuel ratio detectors are disposed in an exhaust system at locations upstream and downstream of a three-way catalyst for detecting a first and second air fuel ratio of an exhaust gas. A target oxygen change amount calculator calculates a target oxygen change amount in a three-way catalyst, and an oxygen change amount calculator calculates an oxygen change mount of the three-way catalyst from an amount of exhaust gas passing through the three-way catalyst in the first air fuel ratio. An air fuel ratio operator inversely controls the air fuel ratio to a rich side and the lean side with a prescribed air fuel ratio width each time the oxygen change amount reaches a target oxygen change amount.
Edwards, II et al., U.S. Pat. No. 7,010,417 discloses a system for determining the maximum available engine output torque that includes an engine speed sensor and a control computer to produce a fueling command for fueling an internal combustion engine. The computer is configured to produce a maximum available engine output torque as a function of the engine speed signal and the fueling command. In another embodiment, the system includes a control computer configured to produce the maximum available engine output torque value as a function of engine speed, at least one engine intake parameter associating an intake manifold coupled to an engine and an exhaust parameter associated with the exhaust gas structure coupled to the engine. And on engine exhaust parameter associated with an exhaust gas structure coupled to the engine. In either case, the engine control strategy is responsive to the maximum available engine torque value to control an engine driven accessory. One of the engine parameters that are examined for determining maximum fueling and/or maximum torque is exhaust parameters such as contents of the exhaust gas.
Hershey, U.S. Pat. No. 6,473,677 discloses a system for determining a maintenance schedule for a jet engine using at least remotely gathered environmental data. The system includes a remote monitor having a sensor for collecting the remotely gathered environmental data. A data pathway is connected to a remote monitor and a processor is connected to the data pathway and processes the remotely gathered environmental data collected by the remote monitor. An environmental database is connected to the data pathway and compiles and stores remotely gathered environmental data. A flight database is connected to the data pathway and compiles and stores flight data for the jet engine. The flight data includes at least thermal cycle data and time on wing data. The processors adapt to generate the maintenance schedule for the jet engine based on the remotely gathered environmental data and flight data.
Blosser, U.S. Pat. No. 5,941,918 discloses a vehicle on board diagnostic system in which the system determines whether the vehicle is continuously in compliance with regulatory emissions standards by sensing only hydrocarbon and carbon monoxide emissions at a position downstream from the three-way catalytic converter. All emission data sensed is correlated to basic vehicle function such as speed and sorted into a number of histograms corresponding to vehicle operating conditions specified by emissions regulations. The histograms are sampled in a statistically validated manner to determine if the vehicle complies with emissions standards. If a failure has occurred, further histogram diagnostic routines are sequentially implement to determine which emission of the vehicle has failed. An indicator is activated to alert the vehicle operator that an emissions failure has occurred.
Betts, et al., U.S. Pat. No. 5,447,031 discloses a dynamic waste gate failure detection apparatus for determining waste gate failure levels for individual internal combustion engines. The apparatus measures and stores intake boost pressures at times when the engine is producing higher boost pressure levels. The apparatus calculates a boost pressure limit value as a function of the stored boost pressures. A waste gate failure is indicated and the engine output power is derated when a boost pressure value exceeds the sum of the boost pressure limit value and a predetermined pressure differential. The ECM derates the engine to 80% of its normal operating abilities in order to prevent pressure from exceeding a level at which engine damage may occur.
Hapka, et al., U.S. Pat. No. 5,070,832 discloses an engine protection system wherein engine performance is derated as a function of the severity of a fluid parameter fault. In one schedule, engine power torque as a function of engine speed is gradually reduced or derated as the fluid parameter moves further out of normal operating range. With this derate schedule the engine will still run and the driver can still operate the vehicle, albeit at lower power levels than a healthy engine. In a second schedule for a severe fault condition, the maximum allowable engine speed is gradually reduced over a certain time period to a certain percentage of the normal maximum engine rpm. Both schedules permit continued operation of the engine in a “limp home” mode for the less severe faults, and as required after a more severe fault, to bring the vehicle safely to a stop. The engine protection system also stores an array of fault information that can be later accessed to investigate engine fluid parameter faults.